The present invention relates to a dental method and means to allow pain-free injections in mucosa by the application of a topical anesthetic followed by an injection limited to penetrate the mucosa only to the extent of penetration of the topical anesthetic.
It is estimated that 50% of dental patients avoid treatment because of the expected pain, especially pain produced by needles and injections. In addition, stress, in the form of pain, reduces a patient""s immunological response. As a result, post-operative recovery times can be extended and the risk of complications increased.
Conventional methods for administering anesthetics to mucosa during dental or oral surgeries employ the application of a topical anesthetic to the mucosa prior to insertion of a hypodermic syringe for delivery of further medications. The depth of penetration of the topical anesthetic ranges typically from 2-4 mm +/xe2x88x921 mm. The depth of penetration of the hypodermic, typically in excess of 4 mm, exceeds this limited depth of penetration of the topical anesthetic. As a result, although the topical anesthetic reduces the amount of pain experienced prior to the hypodermic injection, the procedure is still painful due to the deeper, unlimited penetration of the hypodermic syringe.
Unlike these other systems, the present invention provides a method that controls the depth of penetration of the hypodermic syringe to less than 4 mm. The syringe is limited in depth of penetration to the depth of mucosa anesthetized by the application of the topical anesthetic. As a result, the patient experiences greatly reduced pain. This in turn leads to shortened recovery time, reduced complications and increases the likelihood that patients in need of treatment will actually seek treatment.
Furthermore, conventional methods for limiting the depth of penetration of needles are designed for use with standard medical needles. Standard medical needles differ considerably from dental needles. Most medical needles are large in size, for use in biopsies, catheterizations, establishment of intravenous tubes, and the like, and have a large bore size in the range of 15 to 18 gauge. Dental needles on the other hand are small, having to fit into a patient""s mouth and are of more fragile construction as illustrated by a bore of 27 to 30 gauge. Also, medical needles are typically adjusted to fit the patient and the variable depth, of penetration and have a length greater than 4 mm. Dental needles for anesthetic injections are constant in length, since the depth of penetration required is the same for all patients. Medical needles are typically constructed with a straight shaft, while dental needles include a ring on the shaft to facilitate precise handling during surgery. Medical needles are also constructed for multi-dose vials and the like, while dental needles are specially constructed for set 1.8 mm cartridges. In addition, medical needles are frequently disposable, since the cost of medical procedures allows one-time use. Dental needles, on the other hand, must be re-usable, due to the lower cost requirements and reduced profit margins related to dental procedures. As a result of these marked differences in construction and use requirements between medical and dental needles, the conventional methods for controlling depth of penetration in medical applications are inapplicable to dental anesthetic applications, since the methods are too cumbersome and expensive to be feasible.
The present invention is simple, small and inexpensive, allowing application in dental procedures.
The present invention is a method and means for accomplishing pain-free injection in mucosa, specifically in dental applications. The method is accomplished by applying a topical anesthetic to the desired mucosal area, and following the topical application with an injection, which penetrates the tissues only to the extent of penetration of the topical anesthetic. Various devices of fixed length are described which limit the penetration of the injection such as a drastically truncated syringe needle, a sheath fitted to and covering the needle, a needle shield, and a speculum.